（1）在python中，可以用單引號（’ ’）或者雙引號(“ ”)來表示字符串,效果都是一樣的，可以用‘/’來進行特殊字符的轉義。
>>> 'spam eggs' # single quotes
'spam eggs'
>>> 'doesn\'t' # use \' to escape the single quote...
"doesn't"
>>> "doesn't" # ...or use double quotes instead
"doesn't"
>>> '"Yes," he said.'
'"Yes," he said.'
>>> "\"Yes,\" he said."
'"Yes," he said.'
>>> '"Isn\'t," she said.'
'"Isn\'t," she said.'
（2）如果你不想字符前面加上 \ 將被解釋爲特殊字符，可以通過在第一個引號前面加上r來表示的原始字符串。
>>> print('C:\some\name') # here \n means newline!C:\some
ame
>>> print(r'C:\some\name') # note the r before the quote
C:\some\name
（3）字符串可以跨多個行。一種方法使用三重引號:"""......"""或 ' '...' '。
>>>print("""
Usage: thingy[OPTIONS]
-h Display this usagemessage
-H hostname Hostname to connect to
""")
Usage: thingy[OPTIONS]
-h Display this usagemessage
-H hostname Hostname to connect to
(4)可以通過在字符串的行尾加上“/”來使兩行變成一行。
>>>print("""
Usage: thingy[OPTIONS]\
-h Display this usagemessage
-H hostname Hostname to connect to
""")
Usage: thingy[OPTIONS] -h Display this usagemessage
-H hostname Hostname to connect to
（5）可以連接字符串（粘結在一起）+ 運算符，複製使用 *:
>>>print(3 * 'un' + 'ium')
Unununium
（6）兩個或多個字符串（即封閉引號之間的字符串）緊鄰的將自動連接。
>>> 'Py' 'thon'
'Python'
但是，這僅僅適用於字符串文本之間，不適用於變量以及表達式。
>>> prefix = 'Py'
>>> prefix 'thon' # can't concatenate a variable and a string literal
...
SyntaxError: invalid syntax
>>> ('un' * 3) 'ium'...
SyntaxError: invalid syntax
如果想要連接變量和字符串文本，需要使用+
>>> prefix + 'thon'
'Python'
當你想要打破長字符串時，此功能是特別有用的︰
>>> text = ('Put several strings within parentheses '... 'to have them joined together.')
>>> text
'Put several strings within parentheses to have them joined together.'
（7）字符串可以索引 （下標），第一個字符的下標爲0。Python中沒有單獨的字符類型;字符是大小爲 1 的字符串︰
>>> word = 'Python'
>>> word[0] # character in position 0
'P'
>>> word[5] # character in position 5
'n'
索引也可以是負數，從右邊開始計數，從-1開始︰
>>> word[-1] # last character
'n'
>>> word[-2] # second-last character
'o'
>>> word[-6]
'P'
注意：當索引超出字符串大小時，會報錯。
>>> word[42] # the word only has 6 characters
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
IndexError: string index out of range
（8）除了索引，還支持切片。索引用來獲取單個字符，切片允許您獲取子字符串︰
>>> word[0:2] # characters from position 0 (included) to 2 (excluded)
'Py'
>>> word[2:5] # characters from position 2 (included) to 5 (excluded)
'tho'
可以看出，切片中，開始的位置被包括，而結束的位置不包含。這樣，
s[:i]+s[i:]永遠等於s:
>>> word[:2] + word[2:]
'Python'
>>> word[:4] + word[4:]
'Python'
切片指數具有有用的默認值;省略的第一個索引默認爲零，省略第二個索引默認爲被切成字符串的大小。
>>> word[:2] # 從0到2的字符
'Py'
>>> word[4:] # 從4到結尾的字符
'on'
>>> word[-2:] #從-2到結尾的字符
'on'
不同於索引超出會報錯，切片不一定會報錯：
>>> word[4:42]
'on'
>>> word[42:]
''
但是，負數索引超出的時候，切片會報錯：
>>> print(word[-10,3])
Traceback (most recent call last):
File "<pyshell#39>", line 1, in <module>
print(word[-10,3])
TypeError: string indices must be integers
（9）python中字符串是不可變的，所以不能使用索引或者切片對字符串進行改變。
>>> word[0] = 'J'
...
TypeError: 'str' object does not support item assignment
>>> word[2:] = 'py'
...
TypeError: 'str' object does not support item assignment
如果你需要一個新字符串，你需要重新建一個字符串
>>> 'J' + word[1:]
'Jython'
>>> word[:2] + 'py'
'Pypy'
(10)內建函數len()返回字符串的長度
>>> s = 'supercalifragilisticexpialidocious'
>>> len(s)
34
當然,字符串還有很多其他的性質和方法,以後會繼續講解。